Process for producing styrenic/alkenylnitrile copolymers

Abstract

Disclosed is a process and apparatus for the continuous mass polymerization of styrenic and alkenylnitrile monomers. The process comprises the steps of continuously introducing a feed comprising a predetermined ratio of styrenic and alkenylnitrile monomers into a reaction vessel to produce a reaction mixture; subjecting the reaction mixture to conditions of temperature and pressure under which said monomers copolymerize to produce a styrenic/alkenylnitrile copolymer; subjecting the reaction mixture to agitation; continuously withdrawing styrenic/alkenylnitrile copolymer from the reaction vessel; and by withdrawing vapour phase from the reaction vessel in a controlled amount by varying the amount of cooled surface available for condensing the vapors, condensing the vapors by contact with the cooled surface and returning the condensate to the reaction vessel. The process and apparatus also include a novel means for devolatilizing the product copolymer.

What is claimed is: 
     
       1. A process for controlling reaction temperature in a continuous vinyl monomers polymerization reaction, comprising: (a) introducing a feed comprising vinyl monomers into a reaction vessel to produce a reaction mixture;   (b) subjecting the reaction mixture to conditions of temperature and pressure under which said monomers copolymerize;   (c) cooling the reaction mixture by withdrawing vapor phase from the reaction vessel to a condenser capable of retaining condensed liquids wherein the vapor phase is cooled by contact with a cooled condensing surface to produce a condensed liquid and wherein the rate of withdrawal of vapor phase from the reaction vessel is controlled by controlling the cooled surface area available for contact with the withdrawn vapor phase.   
     
     
       2. The process of claim 1 wherein the cooled surface area available for contact with the withdrawn vapor phase is controlled by varying the amount of retained condensed liquid in the condenser. 
     
     
       3. The process of claim 1 wherein the vapor phase is withdrawn from the reaction vessel to the condenser through an unobstructed line.